One of the main features of this case is the open springboard slot. The design of this case enables it to accommodate almost every single springboard module in existence. If the springboard module doesn't fit the default arrangement, like the Eyemodule, there are pre-drawn grooves on which a razor can be used to cut the rubber off cleanly. I found for the top part that it didn't need to be cut all the way off, just the sides, so that it could bend out of the way when needed.
The basic guidelines for fitting a springboard into the case are here. If the module totally covers the top of the Visor from end to end, it will not work. It the module covers the top of the visor, but only the middle section, the top piece will need to be removed. If the module covers below the base of the springboard slot, the bottom section will need to be removed. Everything else should fit fine with no modifications. An example of why being able to use springboards with this case is the VisorPhone; The VisorPhone will just barely work with this case, but when it does you can close the flip lid while talking to keep the screen clean from face oils.